In other words, he actually makes a positive case for Obama's tenure in office, which is something that's in short supply, even from the Obama campaign (via Matt Yglesias).

First, Tilson provides three big reasons for his support:

1) I believe that he’s a rational, intelligent, moderate person who was dealt a terrible hand and has played it reasonably well, especially in light of implacable political opposition (if I were to grade him, I’d give him a B+);

2) Though I think Mitt Romney is also rational and intelligent, I question whether he is moderate. I think his 47% comment, when he thought the cameras were off, reflects his real views, showing that he has little understanding of or sympathy for those less fortunate than him. I fear that he would attempt to dismantle the New Deal and shred what is left of the safety net, with the result that we would become an even more harsh and unequal society.

I also have grave concerns about both the integrity and core beliefs of someone who, depending on which voters he was trying to appeal to, has espoused vastly different views on countless issues: taxes, women’s rights, abortion, the invasion of Iraq, the role of the federal government in education, campaign spending limits, immigration reform, gay rights, global warming, environmental protection, gun control, even whether he wanted to serve in Vietnam... The list goes on and on, to the point where I can’t tell whether the real Romney is the pragmatic centrist who was the governor of Massachusetts (and who showed up in the debates) or the “severe conservative” he played for years as he campaigned for president – or whether there is any real Mitt Romney at all.

I’ve heard assurances from some moderate Republicans that Romney is really one of them – he was just forced to be a right-winger and pander to the Tea Party in order to win the nomination because otherwise he would have suffered the same fate as Jon Huntsman – but this gives me little solace. If they’re right (and I hope they are, though I’m not willing to bet the future of our country on it!), then he’s been a persuasive liar for the past few years (a sheep in wolf’s clothing). If they’re wrong, then he was a persuasive liar for many years when he ran for Senate and served as governor of Massachusetts (a wolf in sheep’s clothing), and our country could soon be led by a right-wing extremist. Regarding other issues, though I agree with Romney on some (for example, education reform), on most, ranging from how to improve the economy to foreign policy to social issues, I strongly disagree with him (to the extent that I can divine his true views); and

3) Even if Romney is a pragmatic centrist, I question his ability to act independently of a party that I fear has become beholden to people I view as extremists – anti-intellectuals who are hostile to women, minorities, the poor, immigrants, and gays, and who don’t believe in evolution, diplomacy, protecting the environment, equality for women, global warming, and gun control. As Tom Friedman correctly noted, “There is no organic connection between Romney and the G.O.P. base...He is renting the party to fulfill his dream of becoming president, and they’re renting him to get rid of President Obama. But this is not Romney’s party. I don’t see him taking it back to his moderate past.”

The most interesting part is where he really gets into Obama's scorecard on the economy. He argues that it's good, based on the fact that the recovery has been "on par" with past recoveries, even in light of the contraction in the government's contribution to the recovery.

If all those charts don't do it for you, he adds:

For a more valid comparison, look around the world – it was a global recession – and ask yourself which major country has done better than we have? Would you trade places, economically, with Germany, France, the UK, Japan, or China? Relative to other countries, we’re doing reasonably well, as this IMF report documents.